Dados do Trabalho

Título

DOES CPAP MITIGATE CARDIOVASCULAR RESPONSES TO SUBMAXIMAL EFFORT IN SUBJECTS WITH OBSTRUCTIVE SLEEP APNEA? A CROSS-SECTIONAL STUDY

Introdução

Obstructive sleep apnea (OSA) is a clinical condition characterized by repetitive upper airway obstructions during sleep. These transient episodes of hypoxemia-reoxygenation lead to increased oxidative stress, contributing to the development of cardiovascular diseases and reduced exercise tolerance. In this context, continuous positive airway pressure (CPAP), the gold standard treatment for moderate and severe OSA, reduces apnea/hypopnea events and restores the homeostasis of the cardiovascular system.

Objetivo

The aim of this study was to compare cardiovascular responses in OSA subjects with and without CPAP treatment.

Métodos

It was conducted a cross-sectional study in 73 subjects diagnosed with moderate or severe OSA, who showed good adherence (at least 2 months, at least 4 h/night) to CPAP treatment (CPAP group: n = 36) and never used the device (nCPAP group: n= 37). All patients were aged between 30 and 70 years old and BMI between 18 and 45 Kg/m². They underwent the six-minute step test (6MST) and the following variables were assessed: HR, SBP and DBP at rest and one minute after the cessation of 6MST. Data between groups were compared using unpaired t-test or Mann Whitney test. Results are expressed as mean ± standard deviation and confidence interval.

Resultados

The groups were similar in age, weight, height, BMI, waist and neck circumference, excessive daytime sleepiness, apnea/hypopnea index, FEV¹ and FVC. Sleep quality was worst in nCPAP compared to CPAP group (PSQI score: nCPAP 6,19 ± 3,38 vs. CPAP 4,89 ± 3,37 (p = 0,048) and FEV¹/FVC ratio was higher in nCPAP compared to CPAP group (nCPAP 84,85 ± 6,68%predicted vs. CPAP 77,93 ± 9,26%predicted; p = 0,001). Regarding the difference in the resting and first minute after 6MST blood pressure values, as well the SBP (nCPAP 24.2 ± 12,04% vs. CPAP 4.6 ± 7,31%; p = 0.000; CI 14.97 to 24.27), as the DBP (nCPAP = 5.5% ± 0,78% vs. CPAP 0.2% ± 4,33%; p = 0.000; CI 3.22 to 7.48) were higher in nCPAP compared to CPAP group. However, the difference in the resting and first minute after 6MST HR values were the same in the two groups (nCPAP 18.6 ± 15,34% vs. CPAP 15.08 ± 10,59%; p = 0.260; CI -2.65 to 9.68).

Conclusões

The results suggest that OSA individuals treated with CPAP have an attenuated hemodynamic response to submaximal effort and a faster recovery compared to non-treated OSA subjects.

Palavras-chave

obstructive sleep apnea. continuous positive airway pressure. cardiovascular responses. submaximal effort.